/*
 * Copyright 2010-2025 Hyland Software, Inc. and its affiliates.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.asyncexecutor.multitenant;

import java.util.HashMap;
import java.util.Map;
import java.util.Set;
import java.util.concurrent.ExecutorService;
import org.activiti.engine.impl.asyncexecutor.AsyncExecutor;
import org.activiti.engine.impl.asyncexecutor.DefaultAsyncJobExecutor;
import org.activiti.engine.impl.asyncexecutor.ExecuteAsyncRunnableFactory;
import org.activiti.engine.impl.cfg.ProcessEngineConfigurationImpl;
import org.activiti.engine.impl.cfg.multitenant.TenantInfoHolder;
import org.activiti.engine.runtime.Job;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Multi tenant {@link AsyncExecutor}.
 *
 * For each tenant, there will be acquire threads, but only one {@link ExecutorService} will be used
 * once the jobs are acquired.
 *

 */
public class SharedExecutorServiceAsyncExecutor extends DefaultAsyncJobExecutor implements TenantAwareAsyncExecutor {

    private static final Logger logger = LoggerFactory.getLogger(SharedExecutorServiceAsyncExecutor.class);

    protected TenantInfoHolder tenantInfoHolder;

    protected Map<String, Thread> timerJobAcquisitionThreads = new HashMap<String, Thread>();
    protected Map<String, TenantAwareAcquireTimerJobsRunnable> timerJobAcquisitionRunnables = new HashMap<
        String,
        TenantAwareAcquireTimerJobsRunnable
    >();

    protected Map<String, Thread> asyncJobAcquisitionThreads = new HashMap<String, Thread>();
    protected Map<String, TenantAwareAcquireAsyncJobsDueRunnable> asyncJobAcquisitionRunnables = new HashMap<
        String,
        TenantAwareAcquireAsyncJobsDueRunnable
    >();

    protected Map<String, Thread> resetExpiredJobsThreads = new HashMap<String, Thread>();
    protected Map<String, TenantAwareResetExpiredJobsRunnable> resetExpiredJobsRunnables = new HashMap<
        String,
        TenantAwareResetExpiredJobsRunnable
    >();

    public SharedExecutorServiceAsyncExecutor(TenantInfoHolder tenantInfoHolder) {
        this.tenantInfoHolder = tenantInfoHolder;

        setExecuteAsyncRunnableFactory(
            new ExecuteAsyncRunnableFactory() {
                @Override
                public Runnable createExecuteAsyncRunnable(
                    Job job,
                    ProcessEngineConfigurationImpl processEngineConfiguration
                ) {
                    // Here, the runnable will be created by for example the acquire thread, which has already set the current id.
                    // But it will be executed later on, by the executorService and thus we need to set it explicitely again then

                    return new TenantAwareExecuteAsyncRunnable(
                        job,
                        processEngineConfiguration,
                        SharedExecutorServiceAsyncExecutor.this.tenantInfoHolder,
                        SharedExecutorServiceAsyncExecutor.this.tenantInfoHolder.getCurrentTenantId()
                    );
                }
            }
        );
    }

    @Override
    public Set<String> getTenantIds() {
        return timerJobAcquisitionRunnables.keySet();
    }

    public void addTenantAsyncExecutor(String tenantId, boolean startExecutor) {
        TenantAwareAcquireTimerJobsRunnable timerRunnable = new TenantAwareAcquireTimerJobsRunnable(
            this,
            tenantInfoHolder,
            tenantId
        );
        timerJobAcquisitionRunnables.put(tenantId, timerRunnable);
        timerJobAcquisitionThreads.put(tenantId, new Thread(timerRunnable));

        TenantAwareAcquireAsyncJobsDueRunnable asyncJobsRunnable = new TenantAwareAcquireAsyncJobsDueRunnable(
            this,
            tenantInfoHolder,
            tenantId
        );
        asyncJobAcquisitionRunnables.put(tenantId, asyncJobsRunnable);
        asyncJobAcquisitionThreads.put(tenantId, new Thread(asyncJobsRunnable));

        TenantAwareResetExpiredJobsRunnable resetExpiredJobsRunnable = new TenantAwareResetExpiredJobsRunnable(
            this,
            tenantInfoHolder,
            tenantId
        );
        resetExpiredJobsRunnables.put(tenantId, resetExpiredJobsRunnable);
        resetExpiredJobsThreads.put(tenantId, new Thread(resetExpiredJobsRunnable));

        if (startExecutor) {
            startThreadsForTenant(tenantId);
        }
    }

    private void startThreadsForTenant(String tenantId) {
        startTimerJobAcquisitionForTenant(tenantId);
        startAsyncJobAcquisitionForTenant(tenantId);
        startResetExpiredJobsForTenant(tenantId);
    }

    @Override
    public void removeTenantAsyncExecutor(String tenantId) {
        stopThreadsForTenant(tenantId);
    }

    @Override
    public void start() {
        if (isActive) {
            return;
        }

        isActive = true;

        initAsyncJobExecutionThreadPool();

        for (String tenantId : timerJobAcquisitionRunnables.keySet()) {
            startThreadsForTenant(tenantId);
        }
    }

    protected void startTimerJobAcquisitionForTenant(String tenantId) {
        timerJobAcquisitionThreads.get(tenantId).start();
    }

    protected void startAsyncJobAcquisitionForTenant(String tenantId) {
        asyncJobAcquisitionThreads.get(tenantId).start();
    }

    protected void startResetExpiredJobsForTenant(String tenantId) {
        resetExpiredJobsThreads.get(tenantId).start();
    }

    @Override
    protected void stopJobAcquisitionThread() {
        for (String tenantId : timerJobAcquisitionRunnables.keySet()) {
            stopThreadsForTenant(tenantId);
        }
    }

    protected void stopThreadsForTenant(String tenantId) {
        timerJobAcquisitionRunnables.get(tenantId).stop();
        asyncJobAcquisitionRunnables.get(tenantId).stop();
        resetExpiredJobsRunnables.get(tenantId).stop();

        try {
            timerJobAcquisitionThreads.get(tenantId).join();
        } catch (InterruptedException e) {
            logger.warn("Interrupted while waiting for the timer job acquisition thread to terminate", e);
        }

        try {
            asyncJobAcquisitionThreads.get(tenantId).join();
        } catch (InterruptedException e) {
            logger.warn("Interrupted while waiting for the timer job acquisition thread to terminate", e);
        }

        try {
            resetExpiredJobsThreads.get(tenantId).join();
        } catch (InterruptedException e) {
            logger.warn("Interrupted while waiting for the reset expired jobs thread to terminate", e);
        }
    }
}
